The idea that race might be a social construct was proposed in 1972 by a Harvard geneticist named Richard Lewontin. He claimed that the genetic differences between races were so slight that no one working only with genetic data would categorize people as Asians, Whites, Blacks, Mestizos, etc. Lewontin said that racial classification "is now seen to be of virtually no genetic or taxonomic significance."

Leftist racial egalitarians were quick to pick up on Lewontin's words and create a number of rally chants and slogans from them, including "Race is a social construct!" and "There's only One Race, the Human Race!"

The Lewontin Hypothesis almost immediately became a required belief among the politically correct. Unfortunately for them, less than 30 years later it became possible for geneticists and forensic scientists to conduct a statistical analysis of genetic markers in order to see whether their clusters correlated with the commonly identified racial groups.

They did. By 2005, it was well documented that Lewontin had been wrong. Practically every analysis of genetic markers demonstrated the biological reality of racial identities. In one of them, conducted by Tang, Quertermous, and Rodriguez, et. al., in 2005, all except five of 3636 test subjects (including Asians, Whites, Blacks and Mestizos) sorted statistically into the cluster of genetic markers that corresponded to their self-identified racial group. The success rate for predicting how someone would classify himself racially, using only his genes as information, was approximately 99.9 percent, according to that study.

It had long been possible for physical anthropologists to sort skeletal remains by race with very good accuracy, using only the shapes of skull, jaw, teeth and bones as guides. By the first years of the 21st century, it had become possible for forensic experts to do the same thing with DNA, which enabled more accurate identifications of fathers in paternity disputes and in showing police when they have arrested the right suspect, or, sometimes, when they'd nabbed the wrong fellow.

It's true. A forensic scientist with a drop of your blood can tell you your racial ancestry. If race had no genetic basis, that would be an impossible thing to do.

The progress of genetic science since 1972 should have eliminated Richard Lewontin's hypothesis in just the same way that Galileo and his telescopic observations caused the Earth-centered theory of the universe to disappear. Eventually.